Help with replacing an euro cylinder lock...

Discussion in 'Other Trades Talk' started by Alex F, Sep 6, 2021.

  1. Alex F

    Alex F New Member

    Hi everyone,

    I need to replace the euro cylinder lock on my front door but for the life of me I can't seem to find a replacement lock that will fit! I've attached pics for my lock + the measurements.

    It's the first time I'm doing this so naturally I have no experience whatsoever. The size of this lock appears to be around 83mm total... but I can't find any locks that are this size. I have tried 35/50mm locks, 35/45 etc but none of them works!

    Where am I going wrong with this please?

    Any advice would be greatly appreciated.

    Attached Files:

  2. sparky steve

    sparky steve Screwfix Select

  3. Alex F

    Alex F New Member

    Hi! Thanks for your reply.

    I'm afraid it's not helpful as this is one of the maaaany guides I've used when shopping for the replacement lock. :(

    I was hoping someone could tell me something specific about the size or the product I need to buy... because so far, I've tried many different options and they're not working. Perhaps there's something I'm overlooking.

  4. sparky steve

    sparky steve Screwfix Select

    Maybe use the (Need Help contact us link) on their site, or give them a call.
  5. I-Man

    I-Man Screwfix Select

    just go for a 40/50 90mm lock - should not be an issue
  6. AnotherTopJob

    AnotherTopJob Screwfix Select

    What do you mean when you say none of the sizes work? It's 35/45 according to your measurements, so one that size should fit.

    The only slight variation will be how much it protrudes from the front or back of the door. Ideally you want it flush, if there is a lot sticking out, someone could break it off with mole grips etc.
  7. Alex F

    Alex F New Member

    What I mean is that, when installed, it doesn't do what it's supposed to. Like, the deadbolt doesn't move at all, so you can't actually lock the door (but it will close).

    I knew that these aren't supposed to stick out a lot, which is why I'm concerned that trying the 90mm won't be the best idea...

    I'm not sure what to do... I only got the measurements, but whatever I buy doesn't seem to work properly.

    Just curious... why 35/45? I thought you're supposed to measure this from the centre of the hole?
  8. AnotherTopJob

    AnotherTopJob Screwfix Select

    Are there any differences when you compare the locks side by side?

    It looks like your measurements show 35 and 45 from the end to the centre of the hole, and being 80mm total, is close enough to your 83mm measurement.
  9. I-Man

    I-Man Screwfix Select

    the length of the lock shouldn't impact the deadbolt. First try the cylinder while leaving the fixing screw very loose - does the key turn the deadbolt ok? If it's working, then tighten the screw and try again - if it's then stiff or not operating, suggests it's misaligned.
    Truckcab79 likes this.
  10. Truckcab79

    Truckcab79 Active Member

    As anothertopjob and Iman says a cylinder of those dimensions will in theory work. Just that it may stick out more or less than your old one. Assuming that the new one works when it’s not in your door then I’d be looking at what’s stopping it turning in the door mechanism rather than the lock itself. It’s not something stupid like you haven’t unlocked the door handle before fitting or something is it? Many doors lock by first pushing the handle up, then turning the key / thumbturn. The lock is only a cam turning and operating or stopping the mechanism from moving. Can you turn the key if you move the lock back and forth when it’s in position.
    Last edited: Sep 6, 2021
  11. Alex F

    Alex F New Member

    Sorry for not getting back to you earlier!

    I've tried both the 35/45 and 40/50 as suggested above, but to no avail -- the deadbolt still isn't doing anything.

    I've measured my existing lock again and took (hopefully) better pictures. Please see attached. My initial and current impression is that the lock measures 35/50 -- but this was the first one I've tried (from and it did not work. I've also attached a picture with my existing lock and the 35/50 one from side by side.

    @I-Man - I've never bothered to tighten the screw at all, but it still didn't work. It shouldn't make a difference though, as even without tightening the screw on my existing lock, it still works, whereas any of the replacement ones don't.

    I may be stupid, but I can't figure this out and I don't want to pay £££ for someone to get this fixed. I strongly believe it may be something to do with the pins and bolts (?) on the underside of the lock.

    @Truckcab79 - Again, I feel like it may be something to do with the pins and bolts (?) on the underside of the lock.

    I should also mention that my back door has the same kind of cylinder lock as my front door -- and the replacement locks don't work on that door either. :|

    Attached Files:

  12. I-Man

    I-Man Screwfix Select

    Assuming the key turns ok just on it's own, ie. before you putting the cylinder in the door?

    Check for any bits of debris in the door/lock which may be interfering with the cylinder. Are you sure you aligned the cylinder in the right place before trying the key, i.e. the little black cam is aligned with the locking mechanism?
  13. Roys

    Roys Active Member

    I don’t believe it will have anything to do with the pins that you see on the underside, they are part of the actual internal tumblers that the key acts on, they will not protrude outwith the body of the lock.
    From your description it sounds to me that the problem is with the part of the lock that does move and act on the door mechanism, I think the door mechanism is in the wrong position when you put the lock in.
    Have you made sure that the handle has been pressed down to the open position before inserting the lock.
  14. unluckyjim

    unluckyjim New Member

    To find the exact match to what you have Google:
    Mila/BKS 1 Star Euro Cylinder - 84mm (37 x 47)
  15. Alex F

    Alex F New Member

    @I-Man, I don't think it's a debris issue because one lock (my existing one) works and one (the replacement one) doesn't. The same goes for my back door. Logically speaking, I think the black cam should be aligned with the locking mechanism considering I've tried tightening the screw on a few occasions (which wouldn't be possible if the cam weren't aligned with the locking mechanism).

    @Roys, the position of the mechanism isn't the problem (I think) because I've tried pressing the handle down to the open position etc without any result.

    I've ordered the Mila lock recommended by @unluckyjim and will see how it goes. I'll update the thread once I try replacing the lock again, probably by Friday or Monday.

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